EP3152771A1

EP3152771A1 - Device for thermally tripping or disconnecting an overvoltage protection device

Info

Publication number: EP3152771A1
Application number: EP15727926.6A
Authority: EP
Inventors: Uwe Strangfeld; Stephan Hierl
Original assignee: Dehn and Soehne GmbH and Co KG
Current assignee: Dehn SE and Co KG
Priority date: 2014-06-04
Filing date: 2015-05-29
Publication date: 2017-04-12
Anticipated expiration: 2035-05-29
Also published as: CN106415769A; US20170186575A1; US10256062B2; CN106415769B; DE102014008366B3; WO2015185447A1; EP3152771B1

Abstract

The invention relates to a device for thermally disconnecting or tripping an overvoltage protection device, comprising: a locking element (A1), on which a first force (F1) acts, and which is fixed in such a way that same is released when a limit temperature is exceeded; and a slider (S1) which is blocked in a first state (Z1) by the fixed locking element (A1), and on which a second force (F2) acts in order to transfer same into a second state (Z2) when the locking element (A1) is released.

Description

Device for the thermal release or separation of a

Overvoltage protection device

description

The invention relates to a device for thermally triggering or separating an overvoltage protection device with a blocking element, on which a first force acts and which is fixed so that it dissolves when a limit temperature is exceeded; a slider which is locked in a first state by the fixed locking element and on which a second force acts to convert it to a second state when the locking element is released, according to the preamble of claim 1.

DE 10 2006 037 551 B4 shows a locked separating device, wherein a movable solder preform is set by ei ne preloaded spring under force, but this can not escape as long as a bolt blocks the path of movement. If the soldering bolt melts due to a thermal overload caused, for example, by a high current, the solder preform moves, and thus a slide, so that a circuit is closed which, for example, emits a warning signal.

DE 10 2010 061 110 AI also discloses a thermal separation device, wherein a first conductor portion is galvanically coupled to a second conductor portion via a thermally detachable contact. If the temperature is too high, the contact point is released and the first conductor section is conveyed by an always acting on him force in an insulating, so that between the two conductor sections no electrical connection is possible. DE 102005045778 AI relates to a thermal fuse. Two conductor sections are connected via a third conductor section. If too high a temperature, this conductor section is moved by an actuated bolt so that it no longer acts as a connecting element between the other two conductor sections and interrupts a closed circuit over the conductor sections. A controller compares a sensor detected temperature with a predetermined limit temperature and triggers a movement of the bolt when the limit temperature is exceeded. Instead of an active solution with a controller and a sensor can also be a passive solution realized by a biased spring or flexure, in which a relaxation movement is blocked by a mechanical fuse. The mechanical fuse dissolves when a limit temperature is exceeded, whereby the relaxation movement of the spring or bending element conveys the connecting element from the conductor section and thus interrupts the circuit.

Disadvantages of the prior art are, in particular, high costs, susceptibility to maintenance and the lack of robustness of active solutions. Passive solutions, on the other hand, are impaired by the unnecessarily high forces acting on the blocking elements, because at the same time as being interrupted by the forces, a further effect, e.g. a movement of a slider, a switching contact or the like to be performed. This can lead to a "creeping release" of the separator before any relevant thermal overload has occurred.

The object of the present invention is to provide a further developed device for the thermal release or disconnection of an overvoltage protection device, which provides sufficient mechanical forces for actuating a display, a switching contact or the like. This object is achieved by a device for thermal release of a slide of a surge protection device according to claim 1. The dependent claims relate to at least preferred developments.

A device according to the invention for thermally triggering an overvoltage protection device comprises a blocking element. The blocking element is fixed to the device. The fixation has up to a limit temperature to a sufficient function, whereby the blocking element remains firmly up to this Grenztem temperature at its position. If this limit temperature is exceeded, the fixation loses its function, so that the blocking element can be released from its previously assumed position. A first force acts on the blocking element in the fixed state. This force merely indicates that the blocking element is moving out of its original position after the fixation has become inoperative because of too high a temperature.

Furthermore, the device according to the invention comprises a slide, which in a first state is indirectly blocked by the fixed blocking element. A second force is added to the shifter. The second force transfers the slider to a second state, when the locking element is released.

In addition, the device according to the invention has a holding device. This is connected to the slide, in particular detachable or fixed. By t he holding device, the blocking element blocked by the bar bar medium. The Halteein direction is designed so that the second force acting on the slider acts essentially only frictionally and not in the direction of movement of the first force on the locking element.

By the blocking element ka nn z. B. an electric current circle is closed n. This can be done in particular by the fact that the blocking element is designed electrically conductive. Additionally or alternatively, a circuit may be closed by the slider when it is in the first state. This circuit is preferably interrupted when the slider moves to the second state. In particular, this circuit may be interrupted in the second state. The blocking element can also be an electrical component, for. B. a varistor or a Gasabieiter, which is fixed by soldering on a circuit board.

The basic idea of the invention is to decouple the blocking element from the second, larger force required to move the slider and initiate an action. This takes place in that essentially no positive-locking forces which have their origin in the second force act on the blocking element. Only the first force acts form-fitting, that is directly on the blocking element. The second force acts essentially all by friction, a lso iirectly on the blocking element.

Dad has a negative impact of the second force on the fastener, e.g. B. Lot reduced for the blocking element. In particular ka nn as a second force, which is necessary to Beweg ung the slide, a high force can be realized without thereby the blocking element long a us its fixation ged is moved and thereby the device egg ner

"Creeping release".

In one embodiment, according to a first aspect, the first force is generated by a preloaded spring. This can be in particular ei ne compression spring, which provides only the force necessary for Verschiebu of the blocking element force and kei n unnecessary excess force is present. The first force kan n ana log to be effected by a tension spring. In addition or alternatively, the first force can also be generated by a mass, whereby a gravitational force acts on the blocking element. According to a second aspect of this embodiment, the second force may also be provided by a spring pre-tensioned, a tension spring or a pressure spring. can be produced. Additionally or alternatively, this force can also be effected by a mass, in particular by the mass of the slider.

In one embodiment, the holding device comprises at least two forceps-like, resilient jaws, which are supported in the first state against the fixed locking element and against egg ne environment of the slider. An environment in the sense of the invention can be in particular a housing or a housing intermediate wall of the device, or a device which is connected to the device according to the invention. In particular, the jaws are elastically yielding, so that they return to their original state after forced deformation. As a result, the holding element i nsbesondere be reused.

Preferably, the jaws are arranged so that substantially compensates for the normal forces acting on the blocking element. This can be realized in particular by two opposing jaws.

Denkba r is also a Varia nte with three jaws which are each offset by 60 degrees si nd, so that here substantially no resultant force on the blocking element wi rkt. According to the same pri nzi p may also be arranged meh r cheeks, the even closer zusa mmenliegen.

Preferably, one or more cheeks ei ne have a beveled grading, the ng against the environment, in particular a housing or ei ne housing partition, so supported that the second force ei n yielding one or more jaws causes who n this no longer the loosened locking element are blocked. In particular, in the first state a yielding of one or more jaws is blocked, as a result of the fact that they are pressed against the blocking element as a result of the gradation and there is essentially no space for yielding. Effect gradation and blocking element, that the larger, second force is dissipated to the environment and does not affect the fixation of the blocking element,

Vorzugswesse can be a grading part of a groove, which is supported against a corresponding cam of the environment. Alternatively, a grading may be part of a cam that is supported against a corresponding groove of the circumference. In particular, you can rch a groove-cam connection, the holding device and / or the slide at m Einba u be easily and accurately positioned, in particular, without a subsequent shift takes place.

In one embodiment, the temperature-dependent fixation of the barrier element is realized by a solder joint. As a result, it is possible to connect an electrical component directly via the fixing of the blocking element. In particular, this circuit can be interrupted if the fixation is released due to a thermal overload. Alternatively, this current circuit can not be interrupted by fixing the fixing, but preferably only after the blocking element has been moved by the first force. Additionally or alternatively, the fixation can be realized by a temperature sensitive adhesive. In a variant ka n n the fixation, in particular, be realized by a wax compound.

In one embodiment, the device has a wedge surface which lifts the blocking element relative to its surroundings, to which it is fixed in the first state, when it is pressed against the wedge during the transition to the second state. In particular, the wedge colli nea r is the first force which displaces the blocking element. As a result, in particular, the blocking element can be released faster and / or more effectively from the fixation, if a thermal overload has been preceded.

In addition, preferably an electrical connection is more safely disconnected, when an electrical circuit is closed in the first state via the blocking element, in particular by a soldering fixation. In particular, the wedge can counteract arcing when the blocking element is quickly removed from the existing electrical potential.

In one embodiment, the element which generates the first force, that is to say in particular a spring used for this purpose, is supported on the slide. Additionally or alternatively, the force-generating elements may be arranged so that the first force and the second force are parallel, in particular col linear, to each other. As a result, a compact and / or modular construction of the device can be realized.

In egg ner embodiment, the device has a display surface on the respective state (first state, second state) of the slider sig na lisiert. The display surface ka nn in particular fixed or releasably disposed on the slide is n.

In one embodiment, the device has a telecommunication device which signals the respective state (first state, further state) of the device. In particular, the telecommunication device is directly connected to the slider and / or triggered thereby. The telecommunication device is preferably designed to close or interrupt a circuit, so that, after a variation, the circuit is interrupted in the first state and is disconnected in the second state. Because of this, it is not possible to actively switch over to a second state. Additionally or alternatively, it is also possible, please include, that a circuit is closed by the Fernmeldeeinrichtu ng in a first state and in a second state u ter interrupted.

In one embodiment, the blocking element and / or the holding device is friction-coated. As a result, in particular by the holding device, are reduced via the blocking element generated by the second force frictional forces. In particular, an even more extensive decoupling of the second force from the blocking element is possible, so that essentially only the first force acts on the blocking element and rapid removal of the blocking element from the jaws is provided.

According to one embodiment, the contact area between the blocking element and holding device is small. In particular, one or more jaws of the holding device can be designed such that it essentially rests on the blocking element only at one point. Additionally or alternatively, the blocking element may be designed so that the holding device can essentially rest only at one point. Preferably, the blocking element may be wedge-shaped or cone-shaped, so that the transition to the second state, after a first dislocation, the blocking element snaps out of its fixation. In particular, the holding device, in particular one or more jaws, be chamfered so that after a first dislocation in the transition to the second state, the power decoupling is canceled and the blocking element is additionally accelerated by the second force.

Features of various embodiments can be advantageously combined with each other in further, not shown embodiments. Further advantages and features emerge from the subclaims and the exemplary embodiments. This shows, partially schematized:

Fig. 1: an embodiment of the invention in a first

Status;

2 shows an embodiment of the invention with a dissolved

Locking element; 3 shows an embodiment according to the invention during the transition to the second state;

4 shows an embodiment according to the invention in a second embodiment

State and

Fig. 5; a practically realized embodiment of the invention,

1 shows a device for thermal triggering or disconnection of an overvoltage protection device with a display surface and slide (Sl) in the first state (ZI), on which a force (F2) is applied by a spiral spring. The coil spring is supported on a housing (G), in which the slide (Sl) is mounted. The coil spring serves as a force storage, wherein the force (F2) is correspondingly high to move the slider (Sl). The slider (Sl) has a holding device, which is realized by two opposing jaws (B).

On a circuit board (L) is further a blocking element (AI), z. B. in the form of a varistor fixed. The fixing takes place via solder joints, not shown, on two metal conductor tracks (R), which hold and contact the blocking element (AI) at the front and at the back.

The jaws (B) of the holding device (H l) are made resilient, in particular consisting of a flexible plastic material. Furthermore, the jaws (B) each have an outwardly oriented groove. These are there to take in each case a cam (H2), which are realized as part of the housing (G). By the second force (F2), the slider (Sl) is pressed in the direction of the locking element (AI). By the cams (H2), which engage in the groove of the jaws (B), this force is redirected to the jaws (B) so that they are pressed inwards. However, an inward deflection of the jaws (B) is prevented by the locking element (AI) which is arranged between the ends of the jaws (B). As a result, a movement of the jaws (B) is prevented from each other and thus a movement of the slide (Sl). In this first state, in which the blocking element (AI) is fixedly fixed to the wiring carrier, the blocking element (AI) prevents a movement of the jaws (B) of the slide to one another, so the clamps of the jaws can not be compressed. A movement of the slider is excluded by the latching connection (H 1, H2).

The opposing jaws (B) compensate for the normal forces which are applied via the jaws (B) by the second force (F2) on the holding device (H l). As a result, the resulting normal force on the blocking element (AI) disappears. The second force (F2) is thus decoupled from a direct effect on the blocking element (AI) in the first state.

FIG. 2 shows the device for thermal triggering of an overvoltage protection device from FIG. 1. In this case, the fixation of the blocking element (AI) has been achieved by exceeding a Grenztem temperature and the device is in the second state (Z2) on.

Between the jaws (B) is a spring, which is supported on the slide (Sl) and in a prestressed state directly exerts a first force (Fl) on the blocking element (AI). This force leads to a

Acceleration of the locking element (AI), when this is released from the fixation. The spring is dimensioned and the first force (Fl) on the locking element (AI) just to be dimensioned so that the intended effect, namely the acceleration of the locking element (AI) after release of the fixation, occurs. FIG. 3 shows the device according to FIGS. 1 and 2, wherein the state transition is in a second phase. By the first force (Fl), the blocking element (AI) was pushed out of the jaws (B). As a result, the jaws (B) of the holding devices can move inwards. Due to the second force (F2), the jaws (B) are pressed inwards by the locking means, in particular by the cams of the housing, so that the right side of the groove of the jaws (B) no longer blocks movement of the slide (S1). The latching connection (H l) is thus overcome. The second force (F2) accelerates the slider (Sl) and thus also moves the display surface

(A) to the left. This signals z. B. triggering the overvoltage protection device.

Figürlich left next to the fixation of the locking element (AI) is a web (S), which serves to lift the locking element (AI) of its fixation and in particular completely separate. This is done by the blocking element (AI) is pushed by the first force (Fl) on the web (S). This complete separation ensures that the electrical connection that takes place through the fixation is also completely interrupted and thus the closed circuit is also interrupted. In particular, this also excludes arcing.

FIG. 4 shows the device according to FIGS. 1, 2 and 3 in the second state (Z2). The slider (Sl) is fully moved to the left. The flexible baking

(B) of the holding device (Hl) are back in their original form. The blocking element (AI) is accelerated away via the web (S) by the fixing and the wiring carrier, in particular the live printed conductors (R). The force (F2) has a supporting effect. Fig. 5 shows a view of a practically realized embodiment of the invention with partially broken housing (G). In this embodiment, it is a device for overvoltage protection, wherein at least one varistor (V) is used as the overvoltage protection element. This varistor (V) is located inside the housing (G). The actual device for thermally triggering and separating the varistor (V) is also integrated in the housing (G).

The blocking element (AI) is also located in this embodiment on a printed circuit board (L) and Is contacted there existing (not shown in the figure) conductor tracks or pads, in particular by soldering. The slider (Sl) is under the biasing force (F2). Within the slide (Sl) is another, a biasing force (Fl) erzeigendes means, in particular also a spring. This spring presses with its left-side end on an end face of the blocking element (AI). The force (Fl) is less than the force (F2).

The elastic jaws (B) are prevented from moving toward each other by clamping on the blocking element (AI), at least as long as the blocking element (AI) is firmly connected to the printed circuit board (L). When reaching a limit temperature, this particular solder joint dissolves, and the blocking element is moved by means of the force (Fl) from its original position in the direction of the wedge-like web (S) and lifted. As a result, the jaws (B) can now change to such a position that the latching connection (H 1; H2) is canceled and the larger force (F2) on the slider (Sl) allows it to move rapidly. Reference number:

Si slider

AI blocking element

H 1; H2 - locking connection

First force

F2 second force

A display area

R trace; Connection area

G housing

B baking

S footbridge

ZI first state

Z2 second state

V varistor

Claims

claims

1, device for the thermal release or disconnection of an overvoltage protection device with:

- A blocking element (AI), on which a first force (Fl) acts and which is fixed to the device so that it dissolves when a limit temperature is exceeded;

- A slide (Sl) which is blocked in a first state (ZI) by the fixed locking element (AI) and on which a second force acts (F2) to convert this into a second state (Z2) when the blocking element (AI) is solved;

marked by,

a catch holding device (H l) connected to the slide (Sl), by which the blocking element (AI) indirectly blocks the slide and by which the second force (F2) acts as a partial force component clamping on the blocking element (AI), wherein the Rest holding device (H l) has at least two elastic, resilient jaws, which are supported in the first state (ZI) against the fixed locking element (AI) and against an environment (G) of the slide (Sl).

2. Apparatus according to claim 1,

characterized in that

the first force (Fl) and / or the second force (F2) is caused by a prestressed spring and / or by a mass.

3. Apparatus according to claim 1,

characterized in that

the jaws (B) are arranged so that compensate for the blocking element (AI) acting normal forces.

4. Device according to one of claims 1 or 3, characterized in that

a jaw has a step that can be pressed against a fixed point so that the second force (F2) causes a yielding of the jaw, if it is not blocked by the released locking element (AI).

5. Apparatus according to claim 4,

characterized in that

the grading is part of a groove that rests against a corresponding cam of the environment and / or that the grading is part of a cam that rests against a corresponding groove of the environment.

6. Device according to one of the preceding claims,

characterized in that

the temperature-dependent fixing of the blocking element (AI) is realized by a solder joint, an adhesive and / or by a wax compound.

7. Device according to one of the preceding claims,

characterized by a Keilsteg (S), which the blocking element (AI) relative to its surroundings (G), where this is fixed in the first state (ZI) lifts when it is in the transition to the second state (Z2) against the wedge web (S) is pressed.

8. Device according to one of the preceding claims,

characterized in that the force-generating elements are arranged so that the first force (Fl) and the second force (F2) are parallel to each other and Fl <F2.

9. Device according to one of the preceding claims,

characterized by a with the slider (Sl) connected to the display surface, which signals the respective state (ZI, 12) of the device.

10. Device according to one of the preceding claims,

characterized by a Fernmeldeeinrichtu ng, which signals the respective state (ZI, 12) of the device.

11. Device according to one of the preceding claims,

characterized in that

the contact surface between blocking element (Äl) and holding device (H l) is designed punctiform.